As part of our study of fossils, dinosaurs, and creation, the SAIL Pathfinders practiced making field jackets for moving delicate or large fossils from an excavation site. Although our upcoming fossil dig will only be small marine organisms, it was fun to practice a skill used in larger dig sites and for dinosaur and other large fossils.
After gathering our tools, we began by carefully excavating the "fossil" bone, leaving it standing on a pedestal of dirt and rock. We gently cleaned off excesses substrate, being careful not to further damage or chip the "fossil."
After gathering our tools, we began by carefully excavating the "fossil" bone, leaving it standing on a pedestal of dirt and rock. We gently cleaned off excesses substrate, being careful not to further damage or chip the "fossil."
Once the "fossil" was cleaned, the exposed bone was covered with a layer of wet paper towels to protect it from the plaster we used for the jacket (sometimes aluminum foil is used rather than wet paper towels). Near the ends of the bone, we packed gaps with some mud to stabilize the "fossil" and and allow the plaster cast to fit snugly to protect the "fossil."
With the "fossil" bone protected, we made up the plaster mix, cut strips of gauze, and dipped the gauze in plaster to begin wrapping the "fossil" and some of the surrounding substrate to stabilize the bone for final excavation and transport. In a larger field excavation, burlap is often used, instead of the lighter gauze we used for practice.
After ensuring that we had placed the cast around the ends of the "fossil" bone, and strengthened the long shaft, it was ready to set the jacket aside to dry. At our next meeting, we will finish the excavation, and have a "fossil" ready for transport back to the lab!
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